I just returned from a spa vacation, where I accomplished the usual goals: pampering via treatments ranging from massages to facials; lots of exercise, from a few dips in the swim-against-the-current pool to hiking and bicycling; and even a bit of weight loss, from sticking as closely as possible to healthy menu entrees.

But there’s one difference. This spa vacation wasn’t experienced at one of America’s traditional health-oriented fiefdoms, such as Golden Door or Canyon Ranch. Nor was it a resort-with-spa vacation, at a place like West Virginia’s Greenbrier or Colorado’s Broadmoor.

Sea days always book up fast and at full price—as do days in which a formal night is on the agenda.

Some onboard spas have abandoned occasional (and unpredictable) sale prices and moved to a two-tiered pricing level—higher for sea days, lower for port days.

In at least one case—we’ve seen it on Royal Caribbean—spas on newer ships charge significantly higher prices for treatments than on older vessels. For instance, on a recent trip onboard Voyager of the Seas, its spa charged $110 for a 50-minute massage; on a cruise the week before on the older (albeit recently refurbished) Empress of the Seas we paid $99 for the same treatment.

Be forewarned: On ships where Steiner operates spas, its beauty technicians are strongly encouraged to sell their premium-priced products prior to the end of the treatment. The term “hard sell” comes to mind. I had one experience where a Steiner massage therapist actually cut my session short by five minutes to squeeze in the product pitch. Now I just say “no thanks” before the treatment begins.

Ultimately, cruise ship spas, which are a key component of cruising’s ability to offer a health-oriented experience at sea, add a magnificent touch to any cruise. And some—and we offer our editor’s picks of best spas at sea—can absolutely elevate the experience to an even higher level.

Why: Princess’ spa on these two ships genuinely feels like a destination spa – once inside you’ll forget you’re on a cruise ship. We especially love the way the facility is wrapped around its outdoor thalassotherapy pool (which gives it a peaceful, away-from-the-party-crowd ambience all its own). The Lotus Spa concept (seen across the fleet but especially successful here) is quite zen-like and relaxing.

Unique Treatments: What’s unique about the treatments in these two spas is that they, in addition to the usual target of women in terms of treatments, really have made an attempt to cater to men, and even more uniquely, to teens.

Facility: Princess has basically transferred its Grand-class style Lotus Spa concept to these vessels. It’s large and roomy, with check-in and the beauty salon on one side, and treatment rooms, a relaxation room and an aromatic steam room on the other. In between is one of the ship’s best-kept secrets: an outdoor thalassotherapy pool with a swim-against-the-current feature.

With teams using more than 100 unique apparatuses to launch globular projectiles a half-mile or more, the 27th annual World Championship Punkin Chunkin event is our pick as November’s Weird Festival of the Month.

Facility: The spa is compact, as befits the ship’s small size, but efficiently equipped.

Uber-Excellent: Its small size translates directly to very personal service. The spa also offers day-spa-like packages, which is a great incentive to strongly incorporate treatments into a cruise experience. We also loved small and nice touches—such as a bowl of fresh orchids placed directly beneath the table’s face-hole…much nicer than watching the massage therapist’s feet!

Facility: The spa’s thalassotherapy pool—on each ship there’s a different “theme”—is gorgeous. Glass enclosed (so it’s indoors ... with lots of light), it features teak loungers. Otherwise, the spa features all the big-ship accouterments, such as treatment rooms and a full-service beauty salon.

Uber-Excellent: We loved the AquaSpa Cafe—open for breakfast, lunch and early dinner—even when we weren’t using the spa. It offers light and healthy fare.

Needs Improvement: Oddly, the decor of the spa (aside from the thalassotherapy area) is eerily cold and uninviting—evoking the atmosphere of a bare-bones YMCA more than an upscale cruise ship.

Why: Thanks to a recent refurbishment, this spa is the newest in the Crystal fleet and features exotic areas, like a private, canopied teak sundeck and a luxurious new dry float bed suite (for couples or singles).

Unique Treatment: The Absolute Face and Body treatment combines a 60-minute massage with a 30-minute facial.

Facility: The ShipShape Day Spa includes all the facilities—beauty salon, treatment rooms. One of our favorite features is the Thermal Suite with heated tile loungers and tropical and fog showers. What’s different about this particular room—other ships have ‘em too—is that it’s open to the sea, with floor to ceiling glass windows.

Needs Improvement: Royal Caribbean’s fees for spa treatments are higher than industry average.

The grand tradition of the gap year: that glorious time between school and work when young people take an extended break to see the world, explore their options and, perhaps, get a better sense of how they want to live the rest of their lives. These days, more people facing middle age are wondering why young people should have all the fun.